Several types of building panels are presently available that can be used on buildings such as schools, offices, factories and commercial and industrial buildings to cover exterior wall surfaces or window areas in order to reduce heat loss or modify the exterior appearance of the building. The assignee of this application and other companies have sold building panels for such uses which employed a pair of spaced outer layers of polyester resin reinforced with glass fiber material and having a core of plastic foam between the two layers. A more recent development particularly adapted for uses in which a highly fire resistant building panel is required is described in U.S. patent application Ser. No. 296,275 Reeves and Wahner, entitled "Building Panel" filed Aug. 26., 1981, owned by the assignee of this application, which discloses building panels that employ furan resins for the spaced outer layers and includes a covering layer adapted to protect and enhance the appearance of one of the outer layers.
The new building panel which is described hereinbelow differs from the foregoing panels in that it includes only one outer layer that is made with reinforced plastic resin; the other outer layer consists of a metal film which acts as a heat reflective surface. Further, as another distinguishing feature of the present novel building panel, cantilevered retention members are uniquely arranged in the panel and employed as a means of retaining a plastic foam core within the building panel. The general objects of the present invention are to provide building panels including the foregoing features; more specific objects will be apparent from the description which follows.